AN EXPERIMENTAL INVESTIGATION OF THE INTERACTION OF PRIMARY AND SECONDARY STRESSES IN FUEL PLATES

If the load is not relieved as a structure starts to yield, the induce d stress is defined as primary stress. If the load relaxes, as a struc ture begins to yield the induced stress is defined as secondary stress . In design, it is not uncommon to give more weight to primary stresse s than to secondary stresses., However, knowing when this is good desi gn practice and when it is not good design practice represents a probl em. In particular, the fuel plates in operating reactors contain both primary stresses and secondary stresses, and to properly assess a desi gn there is a need to assign design weights to the stresses. Tests wer e conducted on reactor fuel plates intended for the advanced neutron s ource (ANS) to determine the potential of giving different design weig hts to the primary and secondary stresses. The results of these tests and the conclusion that the stresses should be weighted the same are g iven in this paper.